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What are diverticulosis and diverticulitis?

Many people have small pouches in their colons that bulge outward through weak spots, like an inner tube that pokes through weak places in a tire. Each pouch is called a diverticulum. Pouches (plural) are called diverticula. The condition of having diverticula is called diverticulosis. About 10 percent of Americans over the age of 40 have diverticulosis. The condition becomes more common as people age. About half of all people over the age of 60 have diverticulosis.

When the pouches become infected or inflamed, the condition is called diverticulitis. This happens in 10 to 25 percent of people with diverticulosis. Diverticulosis and diverticulitis are also called diverticular disease.

What are the symptoms?

Diverticulosis

Most people with diverticulosis do not have any discomfort or symptoms. However, symptoms may include mild cramps, bloating, and constipation. Other diseases such as irritable bowel syndrome (IBS) and stomach ulcers cause similar problems, so these symptoms do not always mean a person has diverticulosis. You should visit your doctor if you have these troubling symptoms.

Diverticulitis

The most common symptom of diverticulitis is abdominal pain. The most common sign is tenderness around the left side of the lower abdomen. If infection is the cause, fever, nausea, vomiting, chills, cramping, and constipation may occur as well. The severity of symptoms depends on the extent of the infection and complications.

What are the complications?

Diverticulitis can lead to bleeding, infections, perforations or tears, or blockages. These complications always require treatment to prevent them from progressing and causing serious illness.

Bleeding

Bleeding from diverticula is a rare complication. When diverticula bleed, blood may appear in the toilet or in your stool. Bleeding can be severe, but it may stop by itself and not require treatment. Doctors believe bleeding diverticula are caused by a small blood vessel in a diverticulum that weakens and finally bursts. If you have bleeding from the rectum, you should see your doctor. If the bleeding does not stop, surgery may be necessary.

Abscess, Perforation, and Peritonitis

The infection causing diverticulitis often clears up after a few days of treatment with antibiotics. If the condition gets worse, an abscess may form in the colon.

An abscess is an infected area with pus that may cause swelling and destroy tissue. Sometimes the infected diverticula may develop small holes, called perforations. These perforations allow pus to leak out of the colon into the abdominal area. If the abscess is small and remains in the colon, it may clear up after treatment with antibiotics. If the abscess does not clear up with antibiotics, the doctor may need to drain it.

To drain the abscess, the doctor uses a needle and a small tube called a catheter. The doctor inserts the needle through the skin and drains the fluid through the catheter. This procedure is called percutaneous catheter drainage. Sometimes surgery is needed to clean the abscess and, if necessary, remove part of the colon.

A large abscess can become a serious problem if the infection leaks out and contaminates areas outside the colon. Infection that spreads into the abdominal cavity is called peritonitis. Peritonitis requires immediate surgery to clean the abdominal cavity and remove the damaged part of the colon. Without surgery, peritonitis can be fatal.

Fistula

A fistula is an abnormal connection of tissue between two organs or between an organ and the skin. When damaged tissues come into contact with each other during infection, they sometimes stick together. If they heal that way, a fistula forms. When diverticulitis-related infection spreads outside the colon, the colon's tissue may stick to nearby tissues. The organs usually involved are the bladder, small intestine, and skin.

The most common type of fistula occurs between the bladder and the colon. It affects men more than women. This type of fistula can result in a severe, long-lasting infection of the urinary tract. The problem can be corrected with surgery to remove the fistula and the affected part of the colon.

Intestinal Obstruction

The scarring caused by infection may cause partial or total blockage of the large intestine. When this happens, the colon is unable to move bowel contents normally. When the obstruction totally blocks the intestine, emergency surgery is necessary. Partial blockage is not an emergency, so the surgery to correct it can be planned.

What causes diverticular disease?

Although not proven, the dominant theory is that a low-fiber diet is the main cause of diverticular disease. The disease was first noticed in the United States in the early 1900s. At about the same time, processed foods were introduced into the American diet. Many processed foods contain refined, low-fiber flour. Unlike whole-wheat flour, refined flour has no wheat bran.

Diverticular disease is common in developed or industrialized countries—particularly the United States, England, and Australia—where low-fiber diets are common. The disease is rare in countries of Asia and Africa, where people eat high-fiber vegetable diets.

Fiber is the part of fruits, vegetables, and grains that the body cannot digest. Some fiber dissolves easily in water (soluble fiber). It takes on a soft, jelly-like texture in the intestines. Some fiber passes almost unchanged through the intestines (insoluble fiber). Both kinds of fiber help make stools soft and easy to pass. Fiber also prevents constipation.

Constipation makes the muscles strain to move stool that is too hard. It is the main cause of increased pressure in the colon. This excess pressure might cause the weak spots in the colon to bulge out and become diverticula.

Diverticulitis occurs when diverticula become infected or inflamed. Doctors are not certain what causes the infection. It may begin when stool or bacteria are caught in the diverticula. An attack of diverticulitis can develop suddenly and without warning.

How does the doctor diagnose diverticular disease?

To diagnose diverticular disease, the doctor asks about medical history, does a physical exam, and may perform one or more diagnostic tests. Because most people do not have symptoms, diverticulosis is often found through tests ordered for another ailment. For example, diverticulosis is often found during a colonoscopy done to screen for cancer or polyps or to evaluate complaints of pain or rectal bleeding.

When taking a medical history, the doctor may ask about bowel habits, pain, other symptoms, diet, and medications. The physical exam usually involves a digital rectal exam. To perform this test, the doctor inserts a gloved, lubricated finger into the rectum to detect tenderness, blockage, or blood. The doctor may check stool for signs of bleeding and test blood for signs of infection. If diverticulitis is suspected, the doctor may order one of the following radiologic tests:

• Abdominal ultrasound. Sound waves are sent toward the colon through a handheld device that a technician glides over the abdomen. The sound waves bounce off the colon and other organs, and their echoes make electrical impulses that create a picture—called a sonogram—on a video monitor. If the diverticula are inflamed, the sound waves will also bounce off of them, showing their location.

• Computerized tomography (CT) scan. The CT scan is a noninvasive x ray that produces cross-section images of the body. The doctor may inject dye into a vein and the person may be given a similar mixture to swallow. The person lies on a table that slides into a donut-shaped machine. The dye helps to show complications of diverticulitis such as perforations and abscesses.

How is diverticular disease treated?

A high-fiber diet and pain medications help relieve symptoms in most cases of diverticulosis. Uncomplicated diverticulitis with mild symptoms usually requires the person to rest, take oral antibiotics, and be on a liquid diet for a period of time. Sometimes an attack of diverticulitis is serious enough to require a hospital stay, intravenous (IV) antibiotics, and possibly surgery.

Diverticulosis

Increasing the amount of fiber in the diet may reduce symptoms of diverticulosis and prevent complications such as diverticulitis. Fiber keeps stool soft and lowers pressure inside the colon so that bowel contents can move through easily. The American Dietetic Association recommends consuming 20 to 35 grams of fiber each day. The table “What foods have fiber?” shows the amount of fiber in some foods that a person can easily add to the diet.

The doctor may also recommend taking a fiber product such as methylcellulose (Citrucel) or psyllium (Metamucil) one to three times a day. These products are available in powder, pills, or wafers, and provide 2 to 3.5 grams of fiber per dose. Fiber products should be taken with at least 8 ounces of water.

Avoidance of nuts, popcorn, and sunflower, pumpkin, caraway, and sesame seeds has been recommended by physicians out of fear that food particles could enter, block, or irritate the diverticula. However, no scientific data support this treatment measure. Eating a high-fiber diet is the only requirement highly emphasized across the medical literature. Eliminating specific foods is not necessary. The seeds in tomatoes, zucchini, cucumbers, strawberries, and raspberries, as well as poppy seeds, are generally considered harmless. People differ in the amounts and types of foods they can eat. Decisions about diet should be made based on what works best for each person. Keeping a food diary may help identify what foods may cause symptoms.

If cramps, bloating, and constipation are problems, the doctor may prescribe a short course of pain medication. However, some pain medications actually cause constipation.

Diverticulitis

Treatment for diverticulitis focuses on clearing up the inflammation and infection, resting the colon, and preventing or minimizing complications.

Depending on the severity of symptoms, the doctor may recommend bed rest, oral antibiotics, a pain reliever, and a liquid diet. If symptoms ease after a few days, the doctor will recommend gradually increasing the amount of high-fiber foods in the diet.

Severe cases of diverticulitis with acute pain and complications will likely require a hospital stay. Most cases of severe diverticulitis are treated with IV antibiotics and a few days without food or drink to help the colon rest. In some cases, surgery may be necessary.

What foods have fiber?

Examples of foods that have fiber include

Breads, cereals, and beansFiber
1/2 cup of navy beans9.5 grams
1/2 cup of kidney beans8.2 grams
1/2 cup of black beans7.5 grams
Whole-grain cereal, cold
1/2 cup of All-Bran9.6 grams
3/4 cup of Total2.4 grams
3/4 cup of Post Bran Flakes5.3 grams
1 packet of whole-grain cereal, hot3.0 grams
(oatmeal, Wheatena)
1 whole-wheat English muffin4.4 grams

Fruits
1 medium apple, with skin3.3 grams
1 medium pear, with skin4.3 grams
1/2 cup of raspberries4.0 grams
1/2 cup of stewed prunes3.8 grams

Vegetables
1/2 cup of winter squash2.9 grams
1 medium sweet potato with skin4.8 grams
1/2 cup of green peas4.4 grams
1 medium potato with skin3.8 grams
1/2 cup of mixed vegetables4.0 grams
1 cup of cauliflower2.5 grams
1/2 cup of spinach3.5 grams
1/2 cup of turnip greens2.5 grams

When is surgery necessary?

If symptoms of diverticulitis are frequent, or the patient does not respond to antibiotics and resting the colon, the doctor may advise surgery. The surgeon removes the affected part of the colon and joins the remaining sections. This type of surgery—called colon resection—aims to prevent complications and future diverticulitis. The doctor may also recommend surgery for complications such as a fistula or partial intestinal obstruction.

Immediate surgery may be necessary when the patient has other complications, such as perforation, a large abscess, peritonitis, complete intestinal obstruction, or severe bleeding. In these cases, two surgeries may be needed because it is not safe to rejoin the colon right away. During the first surgery, the surgeon cleans the infected abdominal cavity, removes the portion of the affected colon, and performs a temporary colostomy, creating an opening, or stoma, in the abdomen. The end of the colon is connected to the opening to allow normal eating while healing occurs. Stool is collected in a pouch attached to the stoma. In the second surgery several months later, the surgeon rejoins the ends of the colon and closes the stoma.

Points to Remember

• Diverticulosis occurs when small pouches called diverticula bulge outward through weak spots in the colon, or large intestine.
• Most people with diverticulosis never have any discomfort or symptoms.
• Diverticula form when pressure builds inside the colon wall, usually because of constipation.
• The most likely cause of diverticulosis is a low-fiber diet because it increases constipation and pressure inside the colon.
• For most people with diverticulosis, eating a high-fiber diet is the only treatment needed.
• Fiber intake can be increased by eating whole-grain breads and cereals; fruits like apples and pears; vegetables like peas, spinach, and squash; and starchy vegetables like kidney and black beans.
• Diverticulitis occurs when the pouches become inflamed and cause pain and tenderness in the lower left side of the abdomen.
• Diverticulitis can lead to bleeding; infections; small tears, called perforations; or blockages in the colon. These complications always require treatment to prevent them from progressing and causing serious illness.
• Severe cases of diverticulitis with acute pain and complications will likely require a hospital stay. When a person has complications or does not respond to medication, surgery may be necessary.
  

To read the rest of this article (including a list of the fiber content of many foods) from The National Digestive Diseases Information Clearinghouse (NDDIC), please click here: http://digestive.niddk.nih.gov/ddiseases/pubs/diverticulosis/